Preliminary
PT6907
Linear Dimming LED Driver with Switch On/Off
DESCRIPTION
The PT6907 is a buck LED driver which has linear
dimming function with normal switch ON/OFF. While
turning-on the switch first time, the LED current will
increase from the minimum value to the maximum
current during about 7 seconds. The PT6907 builds-in
exponential algorithm and the LED’s brightness
changes smoothly and linearly. During the dimming
processing, you can turn-off the switch when the
LED’s brightness reaches the level you want. The
PT6907 can remember and hold the status for a
certain time which is programmable after turned-off.
You should turn-on the switch again within this holding
time. Then the output stays at remembered level. If
you don’t turn-off the switch during dimming
processing, the output will increase to the maximum
value and hold the status finally.
The PT6907 also integrates 10bit DAC. It is flexible for
synchronous application. You can use only one switch
to control the group LED lamps. They change
synchronously using the power line AC clock.
The PT6907 operates in open loop current mode
control, and the controller achieves good output
current regulation without the need for any loop
compensation. Also, the PT6907 operates in constant
frequency mode. The frequency is set as 50KHz.
FEATURES
•
8V to 12V Input Voltage Range
•
Low Start-up Current
•
Constant Frequency Operation, 50KHz typical
•
Open Loop Peak Current Controller
•
Linear Dimming with Normal Switch On/Off
•
Programmable Holding Time
•
Dimming with Exponential Algorithm, More
Suitable for Human Eyes.
•
10bit DAC Integrated for Synchronous
Application, More Flexible for Group Control
•
Normal Switch Compatible
•
SOP8 Package
APPLICATIONS
•
•
•
•
Offline LED Lamps and Fixtures
Office and Home LED Lightings
LED Table Lamps
Signage and Decorative LED Lightings
BLOCK DIAGRAM
Tel: 886-66296288
‧
Fax: 886-29174598
‧
http://www.princeton.com.tw
‧
2F, 233-1, Baociao Road, Sindian, Taipei 23145, Taiwan
PT6907
ORDER INFORMATION
Valid Part Number
PT6907-S
Package Type
8 Pins, SOP, 150MIL
Top Code
PT6907-S
PIN CONFIGURATION
PIN DESCRIPTION
Pin Name
CS
GND
GNDP
GD
VIN
VDD
VRG
CLK
Description
LED Current Sense. When the voltage of CS pin exceeds the internal threshold voltage, the GD
output goes low.
IC Ground.
IC Ground.
External MOSFET Gate Drive.
Input Supply Voltage 8V~12V/DC.
Output of Internal Regulator.
Status Remember Register. Connect a capacitor to ground. It’s used for internal register during
switch off. The holding time is programmable with this capacitor.
Clock Input for DAC. This pin is connected to AC clock signal to change the output. It is useful
for synchronous application in group control.
Pin No.
1
2
3
4
5
6
7
8
PRE1.2
3
January 2010
PT6907
IMPORTANT NOTICE
Princeton Technology Corporation (PTC) reserves the right to make corrections, modifications, enhancements,
improvements, and other changes to its products and to discontinue any product without notice at any time.
PTC cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a PTC product. No
circuit patent licenses are implied.
Princeton Technology Corp.
2F, 233-1, Baociao Road,
Sindian, Taipei 23145, Taiwan
Tel: 886-2-66296288
Fax: 886-2-29174598
http://www.princeton.com.tw
PRE1.2
4
January 2010
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